What Are the Main Uses and Chemical Properties of Strontium?
The chemical name of Sr is Strontium. Strontium is an element having an atomic number of 38 and atomic mass 87.62 g.mol-1. By nature, Strontium is an alkaline earth metal. Owing to its electronic configuration, Sr element has some specific properties and happens to be highly reactive. It is an alkaline earth metal and is yellowish and silver-white. The metal also reacts with air to produce a dark oxide layer. Physically and chemically, the Sr element is similar to its neighbours on the periodic table—Calcium and barium. Strontium was discovered collaboratively by Adair Crawford and William Cruikshank in 1790.
Sr Chemical Nature
The chemical nature of Strontium is very reactive. In the periodic table, Strontium belongs to group 2. It has a high melting point of 777°C or 1431°F or 1050 K. Strontium belongs to period five and has a boiling point of 1377°C or 2511°F or 1650 K. The density of Sr element (where Sr is the chemical symbol for Strontium) is 2.64 g cm3 and is in the block s of the periodic table. With an atomic number of 38, the relative atomic mass of Strontium is 87.62. The metal has four isotopes--84Sr, 86Sr, 87Sr, 88Sr. Strontium's electronic configuration [Kr] 5s and CAS number 7440-24-6.
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Uses of Strontium
Sr, in chemistry, has many applications. Typical uses of Strontium are listed below:
In Television
Sr chemical name Strontium has the most important application in the production of glass manufacture of cathode ray tubes found in colour television. However, this use of Sr element is gradually on the decline owing to the declining usage of CRTs in televisions. This has consequently significantly affected the way Strontium is mined and refined.
In Fireworks
Strontium is used to create Strontium Carbonate and other Strontium salts which are used to give red colour to fireworks. This property also helps to distinguish Strontium from other elements in a flame test. The production of fireworks constitutes 5 percent of the world's total output.
In Biology and Medicine
Strontium is present in varied quantities in all living organisms. Since Strontium is quite similar to the element calcium, it is located in bones. In Europe and Australia, Strontium ranelate, which is a pharmacologic agent, is used to treat osteoporosis in individuals. However, this method is not allowed in Canada or the United States. In orthopaedic surgery, injectable acrylic bone cement is commonly used to treat prostheses. For arthroplasties of the knee, hip and other joints and fixation of metallic or polymer prosthetics implants to bones, Conventional polymethylmethacrylate (PMMA) is used. However, this method still suffers from certain drawbacks such as a high exothermic reaction and poor attachment of bone cement to the bone surface.
In Geology
Strontium, owing to its strong association with calcium, is very useful in indicating the presence of calcareous rocks, especially those associated with Mg and Ba. In places where Ca, along with other elements give an indication of calcareous rocks and felsic intrusive indicated by other elements, the bedrock geology would be favourable for different elements.
Properties of Strontium
Strontium's atomic number is 38, and Sr's atomic mass is 88. The Sr element (chemical name strontium) has four isotopes which are naturally occurring out of which 88Sr is most commonly found in nature. Chemically there are similarities between Strontium and other heavier alkaline earth metals such as Barium and Calcium. Strontium has a vigorous reaction with water and tarnishes and tarnishes rapidly in air. Strontium is commonly found combined with other elements and compounds owing to the highly reactive nature of the element. Strontium which has been turned into fine powder will ignite spontaneously in air and result in the formation of Strontium nitride and Strontium Oxide. Sr is a metallic lithophile element. An ion of Sr2+ has a size of 118pm which is in between the sizes if calcium ion (100pm) and potassium ion (138pm) and readily substitutes in a large number of minerals which are rock-forming like dolomite, calcium, gypsum, plagioclase and K-feldspar. Sr minerals are comparatively rare, but some of them are SrCO3 and SrSO4, which are included in pegmatites or hydrothermal deposits.
Did You Know?
Here's a very interesting Strontium element fact . Although naturally occurring Strontium (strontium-88) is stable, the Strontium-90 which is synthetic is very radioactive. Strontium-90 is one of the most harmful aspects of nuclear fallout. This is because the human body absorbs Strontium like Calcium. Naturally occurring stable Strontium does not harm us. Owing to the high reactivity of Strontium, it usually occurs only in the form of compounds.
FAQs on Strontium: Properties, Reactions, and Applications
1. What is Strontium (Sr), and where is it found in nature?
Strontium (Sr) is a chemical element with atomic number 38. It is classified as an alkaline earth metal, located in Group 2 of the periodic table, along with elements like Calcium and Magnesium. Due to its high reactivity, Strontium is never found in its pure, elemental form in nature. It primarily occurs in minerals such as celestite (strontium sulfate, SrSO₄) and strontianite (strontium carbonate, SrCO₃).
2. What are the main uses of Strontium and its compounds?
Strontium and its compounds have several important real-world applications. Some key examples include:
- Fireworks and Flares: Strontium salts, particularly strontium nitrate and strontium carbonate, are used to produce a brilliant crimson red colour in pyrotechnics.
- Glow-in-the-Dark Materials: Strontium aluminate is a key component in photoluminescent (glow-in-the-dark) paints and plastics because it can absorb light and release it slowly.
- Ferrite Magnets: It is used in the manufacturing of permanent ferrite magnets.
- Medical Applications: The radioactive isotope Strontium-89 is used in cancer therapy, while Strontium ranelate has been studied for its potential role in treating osteoporosis.
3. What are the key physical and chemical properties of Strontium?
Strontium is a soft, silvery-yellow metal that is highly reactive. Its properties are very similar to those of Calcium and Barium. Key properties include:
- Physical Properties: It is malleable and ductile. When exposed to air, it quickly oxidizes and forms a yellow oxide layer, which is why it must be stored under a liquid hydrocarbon to prevent reaction.
- Chemical Properties: As an alkaline earth metal, it readily reacts with water to form strontium hydroxide and hydrogen gas. It burns in air with a characteristic bright red flame. It combines with halogens, oxygen, and sulfur to form various compounds.
4. Why does Strontium impart a characteristic crimson red colour to a flame?
The characteristic crimson red colour in a flame test is a result of Strontium's electronic structure. When Strontium or its compounds are heated in a flame, the electrons absorb energy and jump to higher, unstable energy levels. They almost immediately fall back to their original, stable energy levels. As they fall back, they release the absorbed energy in the form of light. For Strontium, the specific energy difference corresponds to light in the red part of the visible spectrum, resulting in the distinct crimson flame.
5. How does the chemical similarity of Strontium to Calcium explain its role and risks in biological systems?
Strontium's chemical behaviour is very similar to that of Calcium (Ca) because they are in the same group of the periodic table and have similar ionic radii. The body's biological pathways cannot easily distinguish between the two elements. This means that Strontium can be absorbed and incorporated into bones and teeth, just like calcium. While stable strontium isotopes can be beneficial in some contexts (like osteoporosis treatment), the radioactive isotope Strontium-90 is particularly dangerous. If ingested, it gets deposited in bones, where its long-term radiation can damage bone marrow and lead to bone cancer or leukemia.
6. What is the stable ion of Strontium, and what determines its charge?
The stable ion of Strontium is the strontium cation, Sr²⁺. This charge is determined by its electronic configuration. Strontium has two valence electrons in its outermost shell (the 5s orbital). To achieve the stable electron configuration of the nearest noble gas (Krypton), it readily loses these two electrons. Losing two negatively charged electrons results in a net charge of +2, forming the stable Sr²⁺ ion.
7. How is the radioactive isotope Strontium-90 different from stable Strontium?
The main difference between Strontium-90 (⁹⁰Sr) and stable Strontium (like ⁸⁸Sr) lies in the composition of their atomic nuclei. While both have 38 protons (defining them as Strontium), Strontium-90 has more neutrons, making its nucleus unstable. This instability causes it to undergo radioactive decay, primarily by emitting a high-energy beta particle. This radioactive property makes it both useful and dangerous. It is used in radioisotope thermoelectric generators (RTGs) for power, but it is also a hazardous component of nuclear fallout due to its long half-life of about 29 years and its tendency to accumulate in bones.
